1. Field of Invention
The invention relates to a data transmitting apparatus which transmits bit string data, which is used on the occasion of carrying out transmission of a serial digital video signal which forms bit string data having a bit rate implemented in relation to a standard, and a data receiving apparatus which receives bit string data transmitted from the data transmitting apparatus.
2. Description of Relevant Art
In the field of video signals, from a viewpoint of realizing diversification of information to be transmitted, high quality of reproduced images, etc., efforts of digitization have been made in a proactive manner, and digital video signals, which are formed by digital data representing video signal information, have been proposed with several different systems. For example, a 4:2:2 component digital video signal which is formed by digital data representing video signal information under a standard television system in which the number of lines in each frame is set to 525 lines (hereinafter, referred to as D1 signal), a digital video signal under a HDTV (High Definition Television) system in which the number of lines in each frame is set to 1125 lines (hereinafter, referred to as HD signal), etc. have been known.
The D1 signal is configured, for example, by such a process that word multiplexing processing is applied to Y data series which were made as 10 bit word string data representing a luminance signal component in a video signal, and CB/CR data series which were made as 10 bit word string data representing color difference signal component in the video signal. In addition, the HD signal is formed as word string data which followed a predetermined data format, and there are a Y, CB/CR type one which is composed of the Y data series and the CB/CR data series, and a G, B, R type one which is composed of G data series, B data series and R data series which represent a green color original color signal component, a blue color original color signal component and a red color original color signal component in a video signal.
On the occasion that the suchlike digital video signal is transmitted through a signal transmission path which is configured by an optical signal transmission cable etc. formed by, for example, a coaxial cable and an optical fiber, a structure of the signal transmission path is simplified, and because of that, serial transmission becomes to be desired, in which transmission, a digital video signal is converted from word string data into bit string data (serial digital video signal) and then, transmitted. Then, as to serial transmission of the D1 signal and serial transmission of the HD signal, they are standardized by SMPTE (Society of Motion Picture and Television Engineers) in the United States, respectively, and as to the D1 signal, transmission, which was compliant with SDI (Serial Digital Interface) by SMPTE 259M which is a standard established by SMPTE, is carried out (see, SMPTE STANDARD SMPTE 259M-1997, for Television -10-Bit 4:2:2 Component and 4fsc Composite Digital Signals-Serial Digital Interface), and in addition, as to the HD signal, transmission, which was compliant with HD-SDI (High Definition-Serial Digital Interface) by SMPTE 292M which is a standard established by SMPTE, is carried out (see, SMPTE STANDARD SMPTE 292M-1998, for Television—Bit-Serial Digital Interface for High-Definition Television Systems).
In the transmission which was compliant with SDI, the standard defines that a data rate (bit rate) of a serial digital video signal, which is bit string data being transmitted through a signal transmission path formed by a coaxial cable, an optical transmission cable etc., is set to, for example, 270 Mb/s. That is, on the occasion of transmission of a serial digital video signal to be used for the transmission which was compliant with SDI (hereinafter, referred to as SD signal), a bit rate of the SD signal is to be set to for example, 270 Mb/s. On one hand, on the occasion of the transmission which was compliant with HD-SDI, the standard defines that a bit rate of a serial digital video signal, which is transmitted through a signal transmission path formed by a coaxial cable, an optical signal transmission cable etc., is to be set to 1.485 Gb/s or 1.485/1.001 Gb/s (in this application, both of these bit rates are referred to as 1.485 Gb/s). That is, on the occasion of transmission of a serial digital video signal to be used for the transmission which was compliant with HD-SDI (hereinafter, referred to as HD-SDI signal), a bit rate of the HD-SDI signal is to be set to 1.485 Gb/s.
As to the HD-SDI signal among the SD signal and the HD-SDI signal which are the suchlike serial digital signals, an HD signal, which becomes its basis, is limited to one having a predetermined data format (hereinafter, referred to as source format). A source format, which the suchlike limited HD signal has, is to be defined by parameters of for example, a frame rate: 24 Hz or 24/1.001 Hz (in this application, both of them are referred to as 24 Hz), 25 Hz or 30 Hz or 30/1.001 Hz (in this application, both of them are referred to as 30 Hz), effective line number in each frame: 1080 lines (total line number in each frame: 1125 lines), effective word number in each line: 1920 words, word bit number (quantifying bit number): 10 bits, data format: Y, CB/CR format, and so on.
Under the suchlike situation, as to digital video signals, with the aim of further improvement of resolution of an image which is reproduced on the basis of it, further pursuit of image quality improvement etc., as to parameters which define its data format, it has been proposed to set a frame rate to 60 Hz or 60/1.001 Hz (in this application, both of them are referred to as 60 Hz) or 90 Hz or 90/1.001 Hz (in this application, both of them are referred to as 90 Hz), to make the effective line number in each frame and the effective word number in each line larger than 1080 lines and 1920 words, e.g., approximately twice of 1080 lines and 1920 words, without limited them to 1080 lines and 1920 words, to set the word bit number to bit number which exceeds 10 bits, for example, 12 bits, 14 bits etc., and further, to set a data format to the G, B, R format, and so on. As examples of digital video signals which followed the such proposals, there are one which data format is defined by parameters of for example, frame rate: 60 Hz, effective line number in each frame: 1080 lines, effective word number in each line: 1920 words, word bit number: 12 bit, data format: G, B, R format, etc. (hereinafter, referred to as next generation camera signal), one which data format is defined by parameters of for example, frame rate: 90 Hz, effective line number in each frame: 1080 lines, effective word number in each line: 1920 words, word bit number: 14 bit, data form at: G, B, R format, etc. (hereinafter, referred to as HD super motion signal), and furthermore, one which data format is defined by parameters of for example, frame rate: 24 Hz, effective line number in each frame: 2160 lines, effective word number in each line: 4096 words, word bit number: 12 bit, data format: G, B, R format, etc. (hereinafter, referred to as 4 k×2 k signal), and so on.
Also as to each of these next generation camera signal, HD super motion signal, 4 k×2 k signal etc., on the occasion of its transmission, serial transmission becomes to be desired, in which transmission, a digital video signal is converted from a parallel digital signal forming word string data into a serial digital video signal forming bit string data and then, transmitted.